Wireless device locations services

ABSTRACT

A system for determining location information for a wireless device is described. The system includes a UE, a LE and multiple LMUs. The LE sends, to the LMUs, reception instructions with characteristics of the signal transmission from the UE and each LMU receives, from the LE, the reception instructions. The UE sends a signal transmission. Each LMU receives the transmitted signal from the UE, determines locating information based at least in part on the received signal and sends the locating information to the LE. The LE receives the locating information regarding the transmitted signal and determines a location of the UE based at least in part on the received locating information. Methods, apparatus and computer readable media are also described.

RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application No. 61/198,632, filed on Nov. 6, 2008, which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

The exemplary and non-limiting embodiments of this invention relate generally to wireless communication systems, methods, devices and computer programs and, more specifically, relate to determining location information for a wireless device.

BACKGROUND

This section is intended to provide a background or context to the invention that is recited in the claims. The description herein may include concepts that could be pursued, but are not necessarily ones that have been previously conceived or pursued. Therefore, unless otherwise indicated herein, what is described in this section is not prior art to the description and claims in this application and is not admitted to be prior art by inclusion in this section.

The following abbreviations that may be found in the specification and/or the drawing figures are defined as follows:

3GPP third generation partnership project

A-FLT advanced forward link trilateration

BSR buffer status report

CQI channel quality indicator

DL downlink (eNB towards UE)

DM RS demodulation reference signal

eNB EUTRAN Node B (evolved Node B)

E-OTD enhanced observed time difference

EPC evolved packet core

E-UTRAN evolved UTRAN (LTE)

FCC Federal Communications Commission

GPS global positioning system

GSM global system mobile

LCS location services

LE locating entity

LMU locationing measurement unit

LTE long term evolution

MAC medium access control

MM/MME mobility management/mobility management entity

Node B base station (also eNB)

O&M operations and maintenance

OFDMA orthogonal frequency division multiple access

PDCP packet data convergence protocol

PHY physical

PRACH physical random access channel

PUSCH physical uplink shared channel

RLC radio link control

RRC radio resource control

SC-FDMA single carrier, frequency division multiple access

S-GW serving gateway

SPS semi-persistent scheduling

SRS sounding reference signal

TTI transmission time interval

UE user equipment

UL uplink (UE towards eNB)

U-TDOA uplink time difference of arrival

UTRAN universal terrestrial radio access network

WCDMA wideband code division multiple access

A communication system known as evolved UTRAN (E-UTRAN, also referred to as UTRAN-LTE or as E-UTRA) is currently under development within the 3GPP. As presently specified the DL access technique will be OFDMA, and the UL access technique will be SC-FDMA.

One specification of interest is 3GPP TS 36.300, V8.6.0 (2008-09), 3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Access Network (E-UTRAN); Overall description; Stage 2 (Release 8).

FIG. 1 reproduces FIG. 4.1 of 3GPP TS 36.300, and shows the overall architecture of the E-UTRAN system. The EUTRAN system includes eNBs, providing the E-UTRA user plane (PDCP/RLC/MAC/PHY) and control plane (RRC) protocol terminations towards the UE. The eNBs are interconnected with each other by means of an X2 interface. The eNBs are also connected by means of an S1 interface to an EPC, more specifically to a MME (Mobility Management Entity) by means of a S1 MME interface and to a Serving Gateway (S-GW) by means of a S1 interface. The S1 interface supports a many to many relationship between MMEs/Serving Gateways and eNBs.

The eNB hosts the following functions:

-   -   functions for Radio Resource Management: Radio Bearer Control,         Radio Admission Control, Connection Mobility Control, Dynamic         allocation of resources to UEs in both uplink and downlink         (scheduling);     -   IP header compression and encryption of the user data stream;     -   selection of a MME at UE attachment;     -   routing of User Plane data towards the Serving Gateway;     -   scheduling and transmission of paging messages (originated from         the MME);     -   scheduling and transmission of broadcast information (originated         from the MME or O&M); and     -   a measurement and measurement reporting configuration for         mobility and scheduling.

The technology to locate mobile devices is gaining ground and the development of these technologies is in part driven by the United States Federal Communications Commission (FCC) emergency call requirements, where a terminal placing an emergency call must be positioned with a 67% probability within 50 meters and with a 95% probability within 150 meters. A GPS system could provide such accuracies when the satellites are visible to the receiver, but in indoor/urban environments the probability of determining a GPS position is not high enough to meet these requirements. Additional solutions are needed.

SUMMARY

The below summary section is intended to be merely exemplary and non-limiting.

The foregoing and other problems are overcome, and other advantages are realized, by the use of the exemplary embodiments of this invention.

In a first aspect thereof an exemplary embodiment of this invention provides a system for determining location information for a wireless device. The system includes a first device (e.g., a UE), a second device (e.g., a LE) and a plurality of signal receiving devices (e.g., LMUs). The second device is configured to send, to the plurality of signal receiving devices, reception instructions including characteristics of the signal transmission from the first device. Each signal receiving device of the plurality of signal receiving devices is configured to receive, from the second device, reception instructions including characteristics of a signal transmission. The first device is configured to send a signal on a deterministic time/frequency resource. Each signal receiving device of the plurality of signal receiving devices is configured to detect, from the first device, the timing of the transmitted signal; and to send at least the receive timing information to the second device. The second device is configured to receive, from at least three of the plurality of signal receiving devices, at least their respective receive timing information regarding the transmitted signal of the first device and to determine a location of the first device based at least in part on the received signal timing information.

In another aspect thereof an exemplary embodiment of this invention provides a method for determining location information for a wireless device. The method includes sending, to a plurality of signal receiving devices (e.g., LMUs), reception instructions including characteristics of a signal transmission from a first device (e.g., a UE). Timing information regarding the transmitted signal is received from at least three of the plurality of signal receiving devices. The method also includes determining (e.g., by a processor) a location of the first device based at least in part on the received signal timing information.

In a further aspect thereof an exemplary embodiment of this invention provides a method for determining location information for a wireless device. The method includes receiving, from a first device (e.g., a LE), reception instructions including characteristics of a signal transmission. The transmitted signal is received from a second device (e.g., a UE). The method also includes determining (e.g., by a processor) locating information based at least in part on the received signal timing. The locating information is sent (e.g., via a transmitter) to the first device.

In another aspect thereof an exemplary embodiment of this invention provides an apparatus for determining location information for a wireless device. The apparatus includes one or more processor and one or more memory which includes computer program code. The one or more memory and the computer program code configured to, with the one or more processor, cause the apparatus to perform operations. The operations include to send, to a plurality of signal receiving devices, reception instructions including characteristics of a signal transmission from a first device. Timing information regarding the transmitted signal is received from at least three of the plurality of signal receiving devices. The operations also include determining a location of the first device based at least in part on the received timing information.

In a further aspect thereof an exemplary embodiment of this invention provides an apparatus for determining location information for a wireless device. The apparatus includes one or more processor and one or more memory which includes computer program code. The one or more memory and the computer program code configured to, with the one or more processor, cause the apparatus to perform operations. The operations include to receive, from a first device, reception instructions including characteristics of a signal transmission. The transmitted signal is received from a second device. The operations also include to determine locating information based at least in part on the received signal timing. The locating information is sent to the first device.

In another aspect thereof an exemplary embodiment of this invention provides a computer readable medium tangibly encoding a computer program including program instructions, execution of the program instructions resulting in actions for determining location information for a wireless device. The actions include sending, to a plurality of signal receiving devices, reception instructions including characteristics of a signal transmission from a first device. At least the receive timing information regarding the transmitted signal is received from at least three of the plurality of signal receiving devices. The actions also include determining a location of the first device based at least in part on the received timing information.

In a further aspect thereof an exemplary embodiment of this invention provides a computer readable medium tangibly encoding a computer program including program instructions, execution of the program instructions resulting in actions for determining location information for a wireless device. The actions include receiving, from a first device, reception instructions including characteristics of a signal transmission. The signal transmission is received from a second device. The actions also include determining locating information based at least in part on the received signal timing. The locating information may be sent to the first device.

In another aspect thereof an exemplary embodiment of this invention provides an apparatus for determining location information for a wireless device. The apparatus includes means for sending, to a plurality of signal receiving devices, reception instructions including characteristics of a signal transmission from a first device; means for receiving, from at least three of the plurality of signal receiving devices, timing information regarding the signal transmission; and means for determining a location of the first device based at least in part on the received timing information.

In a further aspect thereof an exemplary embodiment of this invention provides an apparatus for determining location information for a wireless device. The apparatus includes means for receiving, from a first device, reception instructions including characteristics of a signal transmission; means for receiving, from a second device, the transmitted signal; means for determining locating information based at least in part on the received signal timing; and means for sending the locating information to the first device.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other aspects of exemplary embodiments of this invention are made more evident in the following Detailed Description, when read in conjunction with the attached Drawing Figures, wherein:

FIG. 1 reproduces FIG. 4 of 3GPP TS 36.300, and shows the overall architecture of the E UTRAN system.

FIG. 2 shows a simplified block diagram of various exemplary electronic devices that are suitable for use in practicing the exemplary embodiments of this invention.

FIG. 3 shows a more particularized block diagram of an exemplary user equipment such as that shown at FIG. 2.

FIG. 4 illustrates a simplified diagram of a location determining system which includes various exemplary electronic devices that are suitable for use in practicing the exemplary embodiments of this invention.

FIG. 5 depicts a simplified transmission diagram of an exemplary embodiment of this invention.

FIG. 6 is a logic flow diagram that illustrates the operation of a method, and a result of execution of computer program instructions, in accordance with the exemplary embodiments of this invention.

FIG. 7 is a logic flow diagram that illustrates the operation of another method, and a result of execution of computer program instructions, in accordance with the exemplary embodiments of this invention.

DETAILED DESCRIPTION

A network based trilateration solution, where the uplink transmission of the terminal is measured by at least three different measurement units, each having an accurate time reference, offers accurate location determination in city areas where the cell sizes are small and the uplink transmission may be detected by multiple measurement units (typically co-located or even integrated with base stations). Thus, a hybrid solution combining multiple positioning techniques (e.g., network based trilateration and GPS) may meet the FCC emergency call requirements.

An uplink time difference of arrival (U-TDOA) is based on a transmission sent from a terminal and received at multiple sites (regardless of possible macro-diversity). In some systems, a signal processing means may be used to distinguish the signal from any interference (e.g., using post-processing). There may be a number of potential interference sources, for example, other mobile devices. A receiving site may be referred to as a locationing measurement unit (LMU), however, these sites may also provide additional functions.

Based on the time differences in the received transmissions and the known locations of the LMUs, the location of the terminal being positioned may be calculated.

In UTRAN LTE and SC-FDMA systems, an uplink resource may be controlled by one cell. The uplink resource allocation may vary in both time and frequency domains, e.g., a locationing measurement unit (LMU) may have difficulties in detecting signals from terminals. This may be due to: 1) There is no similar user identification based on the spreading (scrambling) code; and/or 2) There is no information outside the serving cell which allocated resources to the UE. Thus, the lack of proper information complicates the task of making location measurements. The detected signal from the UE may be a specific positioning signal or any other signal that is detectable to the LMUs.

In order to provide cellular network based trilateration positioning techniques to a specific radio access technology two problems need to be overcome: 1) the uplink transmission characteristics of the terminal being positioned need to be known in advance by the participating LMUs; and 2) at least three LMUs must be able to detect the signal of the terminal being positioned and measure the received signal timing relative to a common (and accurate) time reference (e.g., a GPS time).

Exemplary embodiments in accordance with this invention are related to the use of an uplink time difference of arrival (U-TDOA) location positioning method, for example as a part of eUTRAN. The U-TDOA may be based on an uplink measurements made in coordination with LMUs. Exemplary embodiments in accordance with this invention may make use of U-TDOA with uplink multiple access, e.g., SC-FDMA. Additionally, exemplary embodiments in accordance with this invention may be used in cooperation with enhanced observed time difference (E-OTD) techniques.

Before describing in further detail the exemplary embodiments of this invention, reference is made to FIG. 2 for illustrating a simplified block diagram of various electronic devices and apparatus that are suitable for use in practicing the exemplary embodiments of this invention.

In the wireless system 230 of FIG. 2, a wireless network 235 is adapted for communication over a wireless link 232 with an apparatus, such as a mobile communication device which may be referred to as a UE 210, via a network access node, such as a Node B (e.g., a base station), and more specifically an eNB 220. The network 235 may include a network control element (NCE) 240 that may include the MME/S GW functionality shown in FIG. 1, and which provides connectivity with a network 235, such as a telephone network and/or a data communications network (e.g., the Internet 238).

The UE 210 includes a controller, such as a computer or a data processor (DP) 214, a computer-readable memory medium embodied as a memory (MEM) 216 that stores a program of computer instructions (PROG) 218, and a suitable wireless interface, such as radio frequency (RF) transceiver 212, for bidirectional wireless communications with the eNB 220 via one or more antennas.

The eNB 220 also includes a controller, such as a computer or a data processor (DP) 224, a computer-readable memory medium embodied as a memory (MEM) 226 that stores a program of computer instructions (PROG) 228, and a suitable wireless interface, such as RF transceiver 222, for communication with the UE 210 via one or more antennas. The eNB 220 is coupled via a data/control path 234 to the NCE 240.

The path 234 may be implemented as the S1 interface shown in FIG. 1. The eNB 220 may also be coupled to another eNB via data/control path 236, which may be implemented as the X2 interface shown in FIG. 1.

The NCE 240 includes a controller, such as a computer or a data processor (DP) 244, a computer-readable memory medium embodied as a memory (MEM) 246 that stores a program of computer instructions (PROG) 248.

At least one of the PROGs 218, 228 and 248 is assumed to include program instructions that, when executed by the associated DP, enable the device to operate in accordance with the exemplary embodiments of this invention, as will be discussed below in greater detail.

That is, the exemplary embodiments of this invention may be implemented at least in part by computer software executable by the DP 214 of the UE 210; by the DP 224 of the eNB 220; and/or by the DP 244 of the eNB 240, or by hardware, or by a combination of software and hardware (and firmware).

The UE 210 and the eNB 220 may also include dedicated processors, for example processors 215 and processors 225.

In general, the various embodiments of the UE 210 can include, but are not limited to, cellular telephones, personal digital assistants (PDAs) having wireless communication capabilities, portable computers having wireless communication capabilities, image capture devices such as digital cameras having wireless communication capabilities, gaming devices having wireless communication capabilities, music storage and playback appliances having wireless communication capabilities, Internet appliances permitting wireless Internet access and browsing, as well as portable units or terminals that incorporate combinations of such functions.

The computer readable MEMs 216, 226 and 246 may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor based memory devices, flash memory, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. The DPs 214, 224 and 244 may be of any type suitable to the local technical environment, and may include one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on a multicore processor architecture, as non-limiting examples. The wireless interfaces (e.g., RF transceivers 212 and 222) may be of any type suitable to the local technical environment and may be implemented using any suitable communication technology such as individual transmitters, receivers, transceivers or a combination of such components.

FIG. 3 illustrates further detail of an exemplary UE in both plan view (left) and sectional view (right), and the invention may be embodied in one or some combination of those more function-specific components. At FIG. 3 the UE 210 has a graphical display interface 320 and a user interface 322 illustrated as a keypad but understood as also encompassing touch-screen technology at the graphical display interface 320 and voice-recognition technology received at the microphone 324. A power actuator 326 controls the device being turned on and off by the user. The exemplary UE 210 may have a camera 328 which is shown as being forward facing (e.g., for video calls) but may alternatively or additionally be rearward facing (e.g., for capturing images and video for local storage). The camera 328 is controlled by a shutter actuator 330 and optionally by a zoom actuator 332 which may alternatively function as a volume adjustment for the speaker(s) 334 when the camera 328 is not in an active mode.

Within the sectional view of FIG. 3 are seen multiple transmit/receive antennas 336 that are typically used for cellular communication. The antennas 336 may be multi-band for use with other radios in the UE. The operable ground plane for the antennas 336 is shown by shading as spanning the entire space enclosed by the UE housing though in some embodiments the ground plane may be limited to a smaller area, such as disposed on a printed wiring board on which the power chip 338 is formed. The power chip 338 controls power amplification on the channels being transmitted and/or across the antennas that transmit simultaneously where spatial diversity is used, and amplifies the received signals. The power chip 338 outputs the amplified received signal to the radio-frequency (RF) chip 340 which demodulates and downconverts the signal for baseband processing. The baseband (BB) chip 342 detects the signal which is then converted to a bit-stream and finally decoded. Similar processing occurs in reverse for signals generated in the apparatus 210 and transmitted from it.

Signals to and from the camera 328 pass through an image/video processor 344 which encodes and decodes the various image frames. A separate audio processor 346 may also be present controlling signals to and from the speakers 334 and the microphone 324. The graphical display interface 320 is refreshed from a frame memory 348 as controlled by a user interface chip 350 which may process signals to and from the display interface 320 and/or additionally process user inputs from the keypad 322 and elsewhere.

Certain embodiments of the UE 210 may also include one or more secondary radios such as a wireless local area network radio WLAN 337 and a Bluetooth® radio 339, which may incorporate an antenna on-chip or be coupled to an off-chip antenna. Throughout the apparatus are various memories such as random access memory RAM 343, read only memory ROM 345, and in some embodiments removable memory such as the illustrated memory card 347. The various programs 218 are stored in one or more of these memories. All of these components within the UE 210 are normally powered by a portable power supply such as a battery 349.

The processors 338, 340, 342, 344, 346, 350, if embodied as separate entities in a UE 210 or eNB 220, may operate in a slave relationship to the main processor 214, 224, which may then be in a master relationship to them. Any or all of these various processors of FIG. 3 access one or more of the various memories, which may be on-chip with the processor or separate therefrom. Similar function-specific components that are directed toward communications over a network broader than a piconet (e.g., components 336, 338, 340, 342-345 and 347) may also be disposed in exemplary embodiments of the access node 220, which may have an array of tower-mounted antennas rather than the two shown at FIG. 3.

Note that the various chips (e.g., 338, 340, 342, etc.) that were described above may be combined into a fewer number than described and, in a most compact case, may all be embodied physically within a single chip.

In an exemplary embodiment in accordance with this invention, an eNode B sends (e.g. via a locating entity (LE)) information to an LMU regarding a resource pattern (e.g., in time, frequency and/or code domains) for a particular terminal. Alternatively, the LMU may be given the time slots when the terminal is scheduled to transmit. The LE may use this information to coordinate additional LMUs for determining the location of the terminal.

When an eNB is made aware of the fact that a particular terminal is being positioned, for example, by a locating entity (LE), the eNB orders the terminal to transmit a signal with the assigned time and frequency characteristics (e.g., TTI, etc.). The signal characteristics the eNB assigns the terminal are also made known to LMUs involved in positioning the terminal.

In addition the eNB may instruct the terminal to boost the power of the uplink transmission in order to increase the probability that a sufficient number of LMUs detect and measure the timing of the terminal's uplink transmission.

A central entity, such as a locationing entity (LE) (e.g., a locationing server) instructs an eNB serving a terminal to be located to instruct the terminal to start transmitting a signal (e.g., transmitting digitally encoded voice frames or a special signal used just for positioning purposes) used in the location measurements. The LE informs at least three LMUs to start seeking for and, if detected, measure the timing of the received signal. The LMUs reports the measurements (e.g., the received timing relative to a common time reference, for example, GPS time) to a location calculation entity (e.g., the LE). The locations of the LMUs may be known and thus the position of the terminal being located can be calculated based on the reception time difference of the terminal's signal as observed by the LMUs.

Signal characteristics to be used for the signal to be detected by the LMUs may be pre-negotiated, assigned from the LE, or decided by the serving eNB and subsequently informed (e.g. via the LE) to the LMUs.

The resources (e.g., time-frequency resources) for positioning may be used to communicate the parameters of the configuration of the SRS or PRACH (using dedicated RRC signaling, broadcast signaling, etc.). If positioning based on a dynamically scheduled PUSCH or DM RS transmission is used, the exact frequency allocation, e.g., subframes as well as the DM RS cyclic shift may be signaled explicitly or by using a predetermined value, in addition to the relevant serving eNB related parameters which may include cell identity and parameters related to DM RS sequence group hopping, sequence hopping and a sequence-shift pattern. The signaling of the parameters between the eNBs may be done over the X2 air interface or via the backhaul network.

The serving eNB may command a UE to transmit a signal that is detectable, occurs relatively often and is of sufficient energy and duration for the LMUs to detect and measure its timing. This may be done by using uplink sounding reference symbols (UL SRS), which may be ordered to be sent periodically over a specific time duration sufficient for the LMUs to measure. Periodic UL SRS may be commanded “on” and subsequently “off”, between these commands the terminal may autonomously transmit using known time and frequency characteristics. Alternatively, the eNB may indicate a duration for the transmission, avoiding transmitting an off command later.

If needed, the eNB may configure UL SRSs or simply turn UL SRSs off for other UEs in order to release sufficient UL SRS resources for the positioning process. The UL SRS resources for the positioning may also be pre-determined.

Another option includes the usage of a dedicated PRACH preamble. The eNB may repeatedly order the UE to transmit a dedicated PRACH preamble on a PRACH channel (or channels). The eNB may send the dedicated PRACH preamble orders to the UE at times known to the LMUs. Also, other dedicated preamble parameters may be pre-negotiated with other LMUs (e.g., during initial setup). Alternatively, the terminal may be scheduled to transmit a message at a predetermined time and frequency. This message may include scheduling information or some other useful information, e.g., an aperiodic CQI report, a Buffer status report (BSR), a demodulation reference signal (DM RS) of a PUSCH transmission, etc.

In another exemplary embodiment in accordance with this invention, a new signal type could be defined for the locationing signal, e.g., on a pre-determined set of sub-frequency/frequencies. The signal could also be an existing signal that is reserved or re-defined solely for positioning. For example, when ordered the UE could send a predetermined PRACH preamble with a predetermined PRACH format using predetermined frequency resources and periodicity repeat the signal over a specific time duration. The relevant parameters could be predetermined relative to the PRACH parameters of the cell or be assigned in a signal using absolute terms. A combination of the signaling mechanisms could also be utilized, e.g., with dedicated PRACH preambles and wideband SRS transmission allowing for a precise positioning estimate. Further, angle or direction of arrival measurements of the UE signal at the LMU could also be utilized as a way to improve the positioning accuracy. These measurements could be used either alone or as a complementary mechanism with the U-TDOA methods to further improve positioning accuracy.

Semi-persistent scheduling (SPS) which defines a deterministic time and frequency transmission pattern may be used by the uplink transmission. The serving eNB could also boost the uplink transmission power of the transmitted signal to enhance the probability that at least three LMUs can detect the signal. The uplink power control commands under the eNBs discretion may be used for this purpose.

FIG. 4 illustrates a simplified diagram of a location determining system 400 which includes various exemplary electronic devices that are suitable for use in practicing an exemplary embodiments in accordance with this invention. As shown, UE 210 is the mobile device which is having its location determined. LMUs 410, 420 and 430 (some of which may be integrated into eNBs) may detect signals in their respective areas (LMU 410 in area 415, LMU 420 in area 425, and LMU 430 in area 435). As show, UE 210 may transmit a signal which may be detected by LMUs 410, 420 and 430. LMUs 410, 420 and 430 may send the receive timing of the detected signal (and any additional information, e.g., the location information for the LMU) to LE 440. LE 440 may be part of a LMU (including LMUs 410, 420 and 430), an eNB, an MME, etc.

FIG. 5 depicts a simplified transmission diagram of an exemplary embodiment in accordance with this invention. As shown, UE 210 is served by eNB 220. At time 510, LE 440 instructs the eNB 220 to order the UE 210 to transmit a signal for locationing purposes. These instructions may include an assignment of signal characteristics. Alternatively, eNB may determine the signal characteristics for the signal and inform the LE accordingly (not shown). As an additional alternative, the LE 440 may instruct the UE 210 directly, for example, where the LE 440 is embodied in the eNB 220.

At time 520, the eNB 220 transmit orders to the UE 210. These orders may include an assignment of signal characteristics (e.g., specific parameters, reference to a predetermined signal characteristics, etc.).

At time 530, the LE 440 instructs at least three LMUs (e.g., 410, 420, 430) to search for a signal from the UE 210. These instructions may include the assigned signal characteristics. Additionally, eNB 220 may also search for the signal from the UE 210 (e.g., using an LMU located in eNB 220). The signaling performed at times 520 and 530 may occur in any timed order (e.g., 530 may occur before 520).

Additionally, eNB 220 may also search for the signal from the UE 210 (e.g., using an LMU located in eNB 220). Accordingly, the LE 440 may elect to not transmit instructions to search for the signal to the eNB 220 if the instructions to order the UE 210 to transmit the signal at time 510 provided sufficient information for the eNB 220 to search for the signal.

In response to receiving orders the UE 210 begins transmitting a signal at time 540. If signal characteristics are provided, then the signal may conform to those characteristics. LMU1 410, LMU2 420 . . . LMUn 430 (and even eNB 220) may then detect the signal from UE 210. Upon receiving the signal, the LMUs may determine the uplink time of arrival of the detected signal against an accurate and common time reference, such as GPS time (not shown).

At time 550, LMU1 410, LMU2 420 . . . LMUn 430 (and even eNB 220) transmit information regarding the received signal (e.g., the time of arrival information) to the LE 440. Additional location information or LMU identifying information may be sent at this time. Based upon at least the received times of arrivals of the transmitted signal as measured by the LMUs, the LE 440 may determine the location of the UE 210 (e.g., using geometric triangulation e.g. based on the Uplink Time Difference of Arrival method and the known locations of the LMUs, etc.). Alternatively, a separate device may receive this information and determine the location of the UE 210.

Based on the foregoing it should be apparent that the exemplary embodiments of this invention provide a method, apparatus and computer program(s) to determining location information for a wireless device.

FIG. 6 is a logic flow diagram that illustrates the operation of a method, and a result of execution of computer program instructions, in accordance with the exemplary embodiments of this invention. In accordance with these exemplary embodiments a method performs, at block 610, instructions comprising an indication of signal characteristics of a signal transmitted from a first device (e.g., UE 210) are sent to a plurality of signal receiving devices (e.g., LMU1 410, LMU2 420, LMUn 430, etc.). Signal timing information of the signal from at least three of the signal receiving devices is received at block 620. At block 630, a location of the first device is determined based at least in part on the received signal timing information. Additionally, the location may be determined at least in part on the signal characteristics (e.g., allocated time domain characteristics). The location of the first device is output at block 640.

FIG. 7 is a logic flow diagram that illustrates the operation of another method, and result of execution of computer program instructions, in accordance with the exemplary embodiments of this invention. At block 710, instructions comprising an indication of signal characteristics of a transmitted signal are received from a first device (e.g., LE 440) are received. The transmitted signal from a second device (e.g., UE 210) is received at block 720. At block 730, signal timing information is determined based at least in part on the received signal. Additionally, the location may be determined at least in part on the signal characteristics (e.g., allocated time domain characteristics). The signal timing information is sent to the first device (e.g., LE 440) at block 740.

The various blocks shown in FIGS. 6 and 7 may be viewed as method steps, and/or as operations that result from operation of computer program code, and/or as a plurality of coupled logic circuit elements constructed to carry out the associated function(s).

An exemplary embodiment in accordance with this invention is a method for determining location information for a wireless device. The method includes sending (e.g., via a transmitter), to a plurality of signal receiving devices (e.g., LMUs), reception instructions including characteristics of a signal transmission from a first device (e.g., a UE). Locating information regarding the signal transmission is received (e.g., via a receiver) from at least three of the plurality of signal receiving devices. The method also includes determining (e.g., by a processor) a location of the first device based at least in part on the received locating information.

In a further exemplary embodiment of the method above, the method also includes sending transmission instructions including the characteristics of the signal transmission to the first device.

In another exemplary embodiment of the method above sending the transmission instructions is performed via a node (e.g., an eNB) serving the first device.

In a further exemplary embodiment of any one of the methods above, the transmission instructions also include instructions to boost transmission power when transmitting the signal.

In another exemplary embodiment of any one of the methods above, the transmission instructions also include instructions to periodically retransmit the signal.

In a further exemplary embodiment of any one of the methods above, the characteristics of the signal transmission include: time domain characteristics and/or frequency domain characteristics.

In another exemplary embodiment of any one of the methods above, the locating information includes: a time difference representing a difference in a transmission time for the transmitted signal and a reception time for the transmitted signal at a signal receiving device and/or a location of the signal receiving device.

In a further exemplary embodiment of any one of the methods above, determining the location of the first device includes performing trilateration of the first device based at least in part on the locating information.

Another exemplary embodiment in accordance with this invention is a method for determining location information for a wireless device. The method includes receiving (e.g., via a receiver), from a first device (e.g., a LE), reception instructions including characteristics of a signal transmission. The signal transmission is received from a second device (e.g., a UE). The method also includes determining (e.g., by a processor) locating information based at least in part on the received transmitted signal. the locating information is sent (e.g., via a transmitter) to the first device.

In a further exemplary embodiment of the method above, the characteristics of the signal transmission include: time domain characteristics and/or frequency domain characteristics.

In another exemplary embodiment of any one of the methods above, determining the locating information includes determining a difference in a transmission time for the transmitted signal and a reception time for the transmitted signal.

In a further exemplary embodiment of any one of the methods above, the locating information includes: a location of the signal receiving device and/or identifier of the signal receiving device.

In another exemplary embodiment of any one of the methods above, the method also includes receiving (e.g., via a receiver), from the first device, a message including transmission instructions with the characteristics of the signal transmission and sending (e.g., via a transmitter) the transmission instructions to the first device.

Another exemplary embodiment in accordance with this invention is an apparatus for determining location information for a wireless device. The apparatus includes one or more processor and one or more memory which includes computer program code. The one or more memory and the computer program code configured to, with the one or more processor, cause the apparatus to perform operations. The operations include to send, to a plurality of signal receiving devices, reception instructions including characteristics of a transmitted signal from a first device. Locating information regarding the transmitted signal are received from at least three of the plurality of signal receiving devices. The operations also include determining a location of the first device based at least in part on the received locating information.

In a further exemplary embodiment of the apparatus above, the at least one memory and the computer program code are also configured to, with the at least one processor, cause the apparatus to send transmission instructions including the characteristics of the transmitted signal to the first device.

In another exemplary embodiment of the apparatus above, sending the transmission instructions is performed via a node serving the first device.

In a further exemplary embodiment of any one of the apparatus above, the transmission instructions also include instructions to boost transmission power when transmitting the transmitted signal.

In another exemplary embodiment of any one of the apparatus above, the transmission instructions also include instructions to periodically retransmit the transmitted signal.

In a further exemplary embodiment of any one of the apparatus above, the characteristics of the transmitted signal include: time domain characteristics and/or frequency domain characteristics.

In another exemplary embodiment of any one of the apparatus above, the locating information includes: a time difference representing a difference in a transmission time for the transmitted signaland a reception time for the transmitted signalat a signal receiving device and/or a location of the signal receiving device.

In a further exemplary embodiment of any one of the apparatus above, determining the location of the first device includes performing trilateration of the first device based at least in part on the locating information.

Another exemplary embodiment in accordance with this invention is an apparatus for determining location information for a wireless device. The apparatus includes one or more processor and one or more memory which includes computer program code. The one or more memory and the computer program code configured to, with the one or more processor, cause the apparatus to perform operations. The operations include to receive, from a first device, reception instructions including characteristics of a transmitted signal. The transmitted signal is received from a second device. The operations also include to determine locating information based at least in part on the received transmitted signal. The locating information is sent to the first device.

In a further exemplary embodiment of the apparatus above, the characteristics of the transmitted signal include: time domain characteristics and/or frequency domain characteristics.

In another exemplary embodiment of any one of the apparatus above, the at least one memory and the computer program code are also configured to, with the at least one processor, cause the apparatus to, when determining the locating information, determine a difference in a transmission time for the transmitted signal and a reception time for the transmitted signal.

In a further exemplary embodiment of any one of the apparatus above, the locating information includes: a location of the signal receiving device and/or identifier of the signal receiving device.

In another exemplary embodiment of any one of the apparatus above, the at least one memory and the computer program code are also configured to, with the at least one processor, cause the apparatus to receive, from the first device, a message including transmission instructions including the characteristics of the signal transmission and to send the transmission instructions to the first device.

Another exemplary embodiment in accordance with this invention is a computer readable medium tangibly encoding a computer program including program instructions, execution of the program instructions resulting in actions for determining location information for a wireless device. The actions include sending, to a plurality of signal receiving devices, reception instructions including characteristics of a signal transmission from a first device. Locating information regarding the transmitted signal is received from at least three of the plurality of signal receiving devices. The actions also include determining a location of the first device based at least in part on the received locating information.

In a further exemplary embodiment of the computer readable medium above, the actions also include sending transmission instructions including the characteristics of the signal transmission to the first device.

In another exemplary embodiment of the computer readable medium above, sending the transmission instructions is performed via a node serving the first device.

In a further exemplary embodiment of any one of the computer readable media above, the transmission instructions also include instructions to boost transmission power when transmitting the signal.

In another exemplary embodiment of any one of the computer readable media above, the transmission instructions also include instructions to periodically retransmit the signal.

In a further exemplary embodiment of any one of the computer readable media above, the characteristics of the signal transmission include: time domain characteristics and/or frequency domain characteristics.

In another exemplary embodiment of any one of the computer readable media above, the locating information includes: a time difference representing a difference in a transmission time for the transmitted signal and a reception time for the transmitted signal at a signal receiving device and/or a location of the signal receiving device.

In a further exemplary embodiment of any one of the computer readable media above, determining the location of the first device includes performing trilateration of the first device

Another exemplary embodiment in accordance with this invention is a computer readable medium tangibly encoding a computer program including program instructions, execution of the program instructions resulting in actions for determining location information for a wireless device. The actions include receiving, from a first device, reception instructions including characteristics of a signal transmission. The transmitted signal is received from a second device. The actions also include determining locating information based at least in part on the received transmitted signal. The locating information is sent to the first device.

In a further exemplary embodiment of the computer readable medium above, the characteristics of the signal transmission include: time domain characteristics and/or frequency domain characteristics.

In another exemplary embodiment of any one of the computer readable media above, determining the locating information includes determining a difference in a transmission time for the transmitted signal and a reception time for the transmitted signal.

In a further exemplary embodiment of any one of the computer readable media above, the locating information includes: a location of the signal receiving device and/or identifier of the signal receiving device.

In another exemplary embodiment of any one of the computer readable media above, the actions also include:

receiving, from the first device, a message including transmission instructions including the characteristics of the signal transmission; and

sending the transmission instructions to the first device.

A further exemplary embodiment in accordance with this invention is an apparatus for determining location information for a wireless device. The apparatus includes means for sending (e.g., a transmitter), to a plurality of signal receiving devices, reception instructions including characteristics of a signal transmission from a first device; means for receiving (e.g., a receiver), from at least three of the plurality of signal receiving devices, locating information regarding the signal transmission; and means for determining (e.g., a processor) a location of the first device based at least in part on the received locating information.

In another exemplary embodiment of the apparatus above, the apparatus also includes means for sending (e.g., a transmitter) transmission instructions including the characteristics of the signal transmission to the first device.

In a further exemplary embodiment of the apparatus above, sending the transmission instructions is performed via a node serving the first device.

In another exemplary embodiment of any one of the apparatus above, the transmission instructions also include instructions to boost transmission power when transmitting the signal.

In a further exemplary embodiment of any one of the apparatus above, the transmission instructions also include instructions to periodically retransmit the signal.

In another exemplary embodiment of any one of the apparatus above, the characteristics of the signal transmission include: time domain characteristics and/or frequency domain characteristics.

In a further exemplary embodiment of any one of the apparatus above, the locating information includes: a time difference representing a difference in a transmission time for the transmitted signal and a reception time for the transmitted signal at a signal receiving device and/or a location of the signal receiving device.

In another exemplary embodiment of any one of the apparatus above, the determining means includes means for performing trilateration (e.g., a processor) of the first device based at least in part on the locating information.

A further exemplary embodiment in accordance with this invention is an apparatus for determining location information for a wireless device. The apparatus includes means for receiving (e.g., a receiver), from a first device, reception instructions including characteristics of a signal transmission; means for receiving (e.g., a receiver), from a second device, the signal transmission; means for determining (e.g., a processor) locating information based at least in part on the received transmitted signal; and means for sending (e.g., a transmitter) the locating information to the first device.

In another exemplary embodiment of the apparatus above, where the characteristics of the signal transmission include: time domain characteristics and/or frequency domain characteristics.

In a further exemplary embodiment of any one of the apparatus above, the determining means includes means for determining (e.g., a processor) a difference in a transmission time for the transmitted signal and a reception time for the transmitted signal.

In another exemplary embodiment of any one of the apparatus above, the locating information includes: a location of the signal receiving device and/or identifier of the signal receiving device.

In a further exemplary embodiment of any one of the apparatus above, the apparatus also includes: means for receiving (e.g., a receiver), from the first device, a message including transmission instructions including the characteristics of the signal transmission; and means for sending (e.g., a transmitter) the transmission instructions to the first device.

Another exemplary embodiment in accordance with this invention is a system for determining location information for a wireless device. The system includes a first device (e.g., a UE), a second device (e.g., a LE) and a plurality of signal receiving devices (e.g., LMUs). The second device is configured to send, to the plurality of signal receiving devices, reception instructions including characteristics of the signal transmission from the first device. Each signal receiving device of the plurality of signal receiving devices is configured to receive, from the second device, reception instructions including characteristics of a signal transmission. The first device is configured to send a signal transmission. Each signal receiving device of the plurality of signal receiving devices is configured to receive, from the first device, the signal transmission, to determine locating information based at least in part on the received signal; and to send the locating information to the second device. The second device is configured to receive, from at least three of the plurality of signal receiving devices, locating information regarding the signal transmission and to determine a location of the first device based at least in part on the received locating information.

In a further exemplary embodiment of the system above, the second device is configured to send transmission instructions including the characteristics of the signal transmission to the first device.

In another exemplary embodiment of the system above, sending the transmission instructions is performed via a node serving the first device.

In a further exemplary embodiment of any one of the systems above, the transmission instructions further include instructions to boost transmission power when transmitting the signal.

In another exemplary embodiment of any one of the systems above, the transmission instructions further include instructions to periodically retransmit the signal.

In a further exemplary embodiment of any one of the systems above, the characteristics of the signal transmission include at least one of: time domain characteristics and frequency domain characteristics.

In another exemplary embodiment of any one of the systems above, the locating information includes at least one of: a time difference representing a difference in a transmission time for the transmitted signal and a reception time for the transmitted signal at a signal receiving device; and a location of the signal receiving device.

In a further exemplary embodiment of any one of the systems above, the second device is configured to determine the location of the first device by performing trilateration of the first device based at least in part on the locating information.

In another exemplary embodiment of any one of the systems above, each signal receiving device of the plurality of signal receiving devices is configured to, when determining the locating information, determine a difference in a transmission time for the transmitted signal and a reception time for the transmitted signal.

In a further exemplary embodiment of any one of the systems above, a signal receiving device of the plurality of signal receiving devices is a serving node (e.g., an eNB) and the serving node is configured to: receive, from the second device, a message including transmission instructions including the characteristics of the signal transmission; and to send the transmission instructions to the first device.

In general, the various exemplary embodiments may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. For example, some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device, although the invention is not limited thereto. While various aspects of the exemplary embodiments of this invention may be illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that these blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

It should thus be appreciated that at least some aspects of the exemplary embodiments of the inventions may be practiced in various components such as integrated circuit chips and modules, and that the exemplary embodiments of this invention may be realized in an apparatus that is embodied as an integrated circuit. The integrated circuit, or circuits, may comprise circuitry (as well as possibly firmware) for embodying at least one or more of a data processor or data processors, a digital signal processor or processors, baseband circuitry and radio frequency circuitry that are configurable so as to operate in accordance with the exemplary embodiments of this invention.

Various modifications and adaptations to the foregoing exemplary embodiments of this invention may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings. However, any and all modifications will still fall within the scope of the non-limiting and exemplary embodiments of this invention.

For example, while the exemplary embodiments have been described above in the context of the EUTRAN (UTRAN-LTE) system, it should be appreciated that the exemplary embodiments of this invention are not limited for use with only this one particular type of wireless communication system, and that they may be used to advantage in other wireless communication systems such as for example (UTRAN, GSM, WCDMA, etc.).

It should be noted that the terms “connected,” “coupled,” or any variant thereof, mean any connection or coupling, either direct or indirect, between two or more elements, and may encompass the presence of one or more intermediate elements between two elements that are “connected” or “coupled” together. The coupling or connection between the elements can be physical, logical, or a combination thereof. As employed herein two elements may be considered to be “connected” or “coupled” together by the use of one or more wires, cables and/or printed electrical connections, as well as by the use of electromagnetic energy, such as electromagnetic energy having wavelengths in the radio frequency region, the microwave region and the optical (both visible and invisible) region, as several non-limiting and non-exhaustive examples.

Further, the various names used for the described parameters (e.g., CQI, etc.) are not intended to be limiting in any respect, as these parameters may be identified by any suitable names. Further, the formulas and expressions that use these various parameters may differ from those expressly disclosed herein. Further, the various names assigned to different channels (e.g., PRACH, etc.) are not intended to be limiting in any respect, as these various channels may be identified by any suitable names.

Furthermore, some of the features of the various non-limiting and exemplary embodiments of this invention may be used to advantage without the corresponding use of other features. As such, the foregoing description should be considered as merely illustrative of the principles, teachings and exemplary embodiments of this invention, and not in limitation thereof. 

What is claimed is:
 1. A method, comprising: sending, to a plurality of signal receiving devices in a E-UTRAN network, reception instructions comprising characteristics of a signal transmission from a first device in the E-UTRAN network, wherein the signal transmission from the first device comprises an uplink sounding reference symbols (SRS); receiving, from at least three of the plurality of signal receiving devices, locating information regarding the signal transmission; and determining a location of the first device based at least in part on the received locating information.
 2. The method of claim 1, further comprising sending transmission instructions comprising the characteristics of the signal transmission to the first device.
 3. The method of claim 2, where sending the transmission instructions is performed via a node serving the first device.
 4. The method of claim 2, where the transmission instructions further comprise instructions to boost transmission power when transmitting the signal.
 5. The method of claim 2, where the transmission instructions further comprise instructions to periodically retransmit the signal.
 6. The method of claim 1, where the characteristics of the signal transmission comprise at least one of: time domain characteristics and frequency domain characteristics.
 7. The method of claim 1, where the locating information comprises at least one of: a time difference representing a difference in a transmission time for the transmitted signal and a reception time for the transmitted signal at a signal receiving device; and a location of the signal receiving device.
 8. The method of claim 1, where determining the location of the first device comprises performing trilateration of the first device based at least in part on the locating information.
 9. A method comprising: receiving, from a first device in a E-UTRAN network, reception instructions comprising characteristics of a signal transmission, wherein the signal transmission from the first device comprises an uplink sounding reference symbols (SRS); receiving, from a second device in the E-UTRAN network, the signal transmission; determining locating information based at least in part on the received transmitted signal; and sending the locating information to the first device.
 10. The method of claim 9, where the characteristics of the signal transmission comprise at least one of: time domain characteristics and frequency domain characteristics.
 11. The method of claim 9, where determining the locating information comprises determining a difference in a transmission time for the transmitted signal and a reception time for the transmitted signal.
 12. The method of claim 9, where the locating information comprises at least one of: a location of the signal receiving device; and identifier of the signal receiving device.
 13. The method of claim 9, further comprising: receiving, from the first device, a message comprising transmission instructions comprising the characteristics of the signal transmission; and sending the transmission instructions to the second device.
 14. An apparatus, comprising: at least one processor; and at least one memory comprising computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to perform at least the following: send, to a plurality of signal receiving devices in a E-UTRAN network, reception instructions comprising characteristics of a signal transmission from a first device in the E-UTRAN network, wherein the signal transmission from the first device comprises an uplink sounding reference symbols (SRS); receive, from at least three of the plurality of signal receiving devices, locating information regarding the signal transmission; and determine a location of the first device based at least in part on the received locating information.
 15. The apparatus of claim 14, where the at least one memory and the computer program code are further configured to, with the at least one processor, cause the apparatus to send transmission instructions comprising the characteristics of the signal transmission to the first device.
 16. The apparatus of claim 15, where sending the transmission instructions is performed via a node serving the first device.
 17. The apparatus of claim 15, where the transmission instructions further comprise instructions to boost transmission power when transmitting the signal.
 18. The apparatus of claim 15, where the transmission instructions further comprise instructions to periodically retransmit the signal.
 19. The apparatus of claim 14, where the characteristics of the signal transmission comprise at least one of: time domain characteristics and frequency domain characteristics.
 20. The apparatus of claim 14, where the locating information comprises at least one of: a time difference representing a difference in a transmission time for the transmitted signal and a reception time for the transmitted signal at a signal receiving device; and a location of the signal receiving device.
 21. The apparatus of claim 14, where determining the location of the first device comprises performing trilateration of the first device based at least in part on the locating information.
 22. An apparatus, comprising: at least one processor; and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to perform at least the following: receive, from a first device in a E-UTRAN network, reception instructions comprising characteristics of a signal transmission, wherein the signal transmission from the first device comprises an uplink sounding reference symbols (SRS); receive, from a second device in the E-UTRAN network, the signal transmission; determine locating information based at least in part on the received signal transmission; and send the locating information to the first device.
 23. The apparatus of claim 22, where the characteristics of the signal transmission comprise at least one of: time domain characteristics and frequency domain characteristics.
 24. The apparatus of claim 22, where the at least one memory and the computer program code are further configured to, with the at least one processor, cause the apparatus to, when determining the locating information, determine a difference in a transmission time for the transmitted signal and a reception time for the transmitted signal.
 25. The apparatus of claim 22, where the locating information comprises at least one of: a location of the signal receiving device; and identifier of the signal receiving device.
 26. The apparatus of claim 22, where the at least one memory and the computer program code are further configured to, with the at least one processor, cause the apparatus to: receive, from the first device, a message comprising transmission instructions comprising the characteristics of the signal transmission; and send the transmission instructions to the second device.
 27. A computer readable medium tangibly encoded with a computer program executable by a processor to perform actions comprising: sending, to a plurality of signal receiving devices in a E-UTRAN network, reception instructions comprising characteristics of a signal transmission from a first device in the E-UTRAN network, wherein the signal transmission from the first device comprises an uplink sounding reference symbols (SRS); receiving, from at least three of the plurality of signal receiving devices, locating information regarding the signal transmission; and determining a location of the first device based at least in part on the received locating information.
 28. The computer readable medium of claim 27, where the actions further comprise sending transmission instructions comprising the characteristics of the signal transmission to the first device.
 29. The computer readable medium of claim 28, where sending the transmission instructions is performed via a node serving the first device.
 30. The computer readable medium of claim 28, where the transmission instructions further comprise instructions to boost transmission power when transmitting the signal.
 31. The computer readable medium of claim 28, where the transmission instructions further comprise instructions to periodically retransmit the signal.
 32. The computer readable medium of claim 27, where the characteristics of the signal transmission comprise at least one of: time domain characteristics and frequency domain characteristics.
 33. The computer readable medium of claim 27, where the locating information comprises at least one of: a time difference representing a difference in a transmission time for the transmitted signal and a reception time for the transmitted signal at a signal receiving device; and a location of the signal receiving device.
 34. The computer readable medium of claim 27, where determining the location of the first device comprises performing trilateration of the first device based at least in part on the locating information.
 35. A computer program product embodied on a non-transitory computer readable medium tangibly encoded with a computer program configured to provide instructions to control or carry out when executable by a processor to perform actions comprising: receiving, from a first device in a E-UTRAN network, reception instructions comprising characteristics of a signal transmission, wherein the signal transmission from the first device comprises an uplink sounding reference symbols (SRS); receiving, from a second device in the E-UTRAN network, the signal transmission; determining locating information based at least in part on the received transmitted signal; and sending the locating information to the first device.
 36. The computer program product of claim 35, where the characteristics of the signal transmission comprise at least one of: time domain characteristics and frequency domain characteristics.
 37. The computer program product of claim 35, where determining the locating information comprises determining a difference in a transmission time for the transmitted signal and a reception time for the transmitted signal.
 38. The computer program product of claim 35, where the locating information comprises at least one of: a location of the signal receiving device; and identifier of the signal receiving device.
 39. The computer program product of claim 35, where the actions further comprise: receiving, from the first device, a message comprising transmission instructions comprising the characteristics of the signal transmission; and sending the transmission instructions to the second device.
 40. An apparatus comprising: means for sending, to a plurality of signal receiving devices in a E-UTRAN network, reception instructions comprising characteristics of a signal transmission from a first device in the E-UTRAN network, wherein the signal transmission from the first device comprises an uplink sounding reference symbols (SRS); means for receiving, from at least three of the plurality of signal receiving devices, locating information regarding the signal transmission; and means for determining a location of the first device based at least in part on the received locating information.
 41. The apparatus of claim 40, further comprising means for sending transmission instructions comprising the characteristics of the signal transmission to the first device.
 42. The apparatus of claim 41, where sending the transmission instructions is performed via a node serving the first device.
 43. The apparatus of claim 41, where the transmission instructions further comprise instructions to boost transmission power when transmitting the signal.
 44. The apparatus of claim 41, where the transmission instructions further comprise instructions to periodically retransmit the signal.
 45. The apparatus of claim 40, where the characteristics of the signal transmission comprise at least one of: time domain characteristics and frequency domain characteristics.
 46. The apparatus of claim 40, where the locating information comprises at least one of: a time difference representing a difference in a transmission time for the transmitted signal and a reception time for the transmitted signal at a signal receiving device; and a location of the signal receiving device.
 47. The apparatus of claim 40, where the determining means comprises means for performing trilateration of the first device based at least in part on the locating information.
 48. An apparatus comprising: means for receiving, from a first device in a E-UTRAN network, reception instructions comprising characteristics of a signal transmission, wherein the signal transmission from the first device comprises an uplink sounding reference symbols (SRS); means for receiving, from a second device in the E-UTRAN network, the signal transmission; means for determining locating information based at least in part on the received transmitted signal; and means for sending the locating information to the first device.
 49. The apparatus of claim 48, where the characteristics of the signal transmission comprise at least one of: time domain characteristics and frequency domain characteristics.
 50. The apparatus of claim 48, where the determining means comprises means for determining a difference in a transmission time for the transmitted signal and a reception time for the transmitted signal.
 51. The apparatus of claim 48, where the locating information comprises at least one of: a location of the signal receiving device; and identifier of the signal receiving device.
 52. The apparatus of claim 48, further comprising: means for receiving, from the first device, a message comprising transmission instructions comprising the characteristics of the signal transmission; and means for sending the transmission instructions to the second device.
 53. A system comprising: a first device, a second device and a plurality of signal receiving devices in a E-UTRAN network, where the second device is configured to send, to the plurality of signal receiving devices, reception instructions comprising characteristics of the signal transmission from the first device, wherein the signal transmission from the first device comprises an uplink sounding reference symbols (SRS); each signal receiving device of the plurality of signal receiving devices is configured to receive, from the second device, reception instructions comprising characteristics of a signal transmission; the first device is configured to transmit a signal; each signal receiving device of the plurality of signal receiving devices is configured to receive, from the first device, the signal transmission, to determine locating information based at least in part on the received transmitted signal; and to send the locating information to the second device; and the second device is configured to receive, from at least three of the plurality of signal receiving devices, locating information regarding the signal transmission and to determine a location of the first device based at least in part on the received locating information.
 54. The system of claim 53, where the second device is configured to send transmission instructions comprising the characteristics of the signal transmission to the first device.
 55. The system of claim 54, where sending the transmission instructions is performed via a node serving the first device.
 56. The system of claim 54, where the transmission instructions further comprise instructions to boost transmission power when transmitting the signal.
 57. The system of claim 54, where the transmission instructions further comprise instructions to periodically retransmit the signal.
 58. The system of claim 53, where the characteristics of the signal transmission comprise at least one of: time domain characteristics and frequency domain characteristics.
 59. The system of claim 53, where the locating information comprises at least one of: a time difference representing a difference in a transmission time for the transmitted signal and a reception time for the transmitted signal at a signal receiving device; and a location of the signal receiving device.
 60. The system of claim 53, where the second device is configured to determine the location of the first device by performing trilateration of the first device based at least in part on the locating information.
 61. The system of claim 53, where each signal receiving device of the plurality of signal receiving devices is configured to, when determining the locating information, determine a difference in a transmission time for the transmitted signal and a reception time for the transmitted signal.
 62. The system of claim 53, where a signal receiving device of the plurality of signal receiving devices is a serving node and the serving node is configured to: receive, from the second device, a message comprising transmission instructions comprising the characteristics of the signal transmission; and to send the transmission instructions to the first device. 